Researchers Create Means to Monitor Anthropogenic Global Warming in Real Time [Associate Professor Yu Kosaka (Climate Science Research)]

The globally averaged surface temperature has risen since the Industrial Revolusion. The rise is, however, not smooth, but resembles a rising staircase. Associate Professor Yu Kosaka (Climate Science Research, RCAST) and Prof. Shang-Ping Xie (Scripps Institution of Oceanography at the University of California San Diego) simulated in a computer model, for the first time, the realistic evolution of the global mean surface temperature since 1900. They identified the tropical Pacific natural variability as an essential "pacemaker" of the staircase-like global warming.

Using the model simulations and the observations, they further proposed a novel method to isolate the anthropogenic warming by removing the internally generated natural variability. Climate policymakers have sought to limit the rise of global temperatures to below 2°C above pre-industrial levels. Scientists have estimated that the planet is already roughly 1°C warmer at the surface than before the Industrial Revolution. However, Kosaka and Xie's calculation yields a much higher anthropogenic warming of 1.2°C for the recent five-year period of 2010-2014 relative to around 1900, after correcting for the natural variability effect. The research could provide an easily generated and more accurate means to monitor the state of anthropogenic climate change.

The paper, "The tropical Pacific as a key pacemaker of the variable rates of global warming," appears in the journal Nature Geoscience.

DOI：https://dx.doi.org/10.1038/ngeo2770